Expression of microRNAs miR-126, miR-133b and miR-221 associated with apoptosis in rats submitted to focal cerebral ischemia and physical exercise / Expresión de microRNAs miR-126, miR-133b y miR-221 asociados a apoptosis en ratas sometidas a isquemia cerebral focal y ejercicio físico

SUMMARY: Stroke is one of the main causes of death and disability worldwide. The great impact on the quality of life of the population and on the health system justifies that we seek relevant alternatives to reduce the incidence and improve the treatment and recovery of patients affected by this disease. Physical exercise appears as an important tool in this scenario, being already pointed out as a possible therapeutic approach for the prevention of non-contagious chronic diseases. In this context, biomarkers such as miRNAs that respond to physical exercise and are directly related to several epigenetic mechanisms appear. Therefore, explaining the molecular mechanisms involved during physical exercise will lead to a better understanding of each stimulus and the dose to be used to better respond to each situation, thus being a promising approach for the evolution of prescription and control of training and processes recovery from various diseases, including stroke. Forty-eight Wistar rats were used, divided into four experimental groups: control group, ischemia group, physical exercise group and exercise + ischemia group. Real-time PCR methodology was used to analyze the expression of miRNAs: miR-126, miR-133b and miR-221. In our study we observed a significant difference in the expression of miR- 221 between the control group and the others groups. However, microRNAs: miR-126 and miR-133b do not show significant differences in expression between groups.

El ictus es una de las principales causas de muerte y discapacidad en todo el mundo. El gran impacto en la calidad de vida de la población y en el sistema de salud justifica buscar alternativas pertinentes para reducir la incidencia y mejorar el tratamiento y recuperación de los pacientes afectados por esta enfermedad. El ejercicio físico aparece como una herramienta importante en este escenario, siendo ya señalado como un posible abordaje terapéutico para la prevención de enfermedades crónicas no contagiosas. En este contexto, aparecen biomarcadores como los miRNAs que responden al ejercicio físico y están directamente relacionados con varios mecanismos epigenéticos. Por lo tanto, explicar los mecanismos moleculares involucrados durante el ejercicio físico conducirá a una mejor comprensión de cada estímulo y la dosis a utilizar para responder mejor a cada situación, siendo así un enfoque prometedor para la evolución de la prescripción, el control del entrenamiento y los procesos de recuperación de diversas enfermedades, incluido el accidente cerebrovascular. Se utilizaron cuarenta y ocho ratas Wistar, divididas en cuatro grupos experimentales: grupo control, grupo isquemia, grupo ejercicio físico y grupo ejercicio + isquemia. Se utilizó la metodología de PCR en tiempo real para analizar la expresión de miRNAs: miR-126, miR-133b y miR-221. En nuestro estudio observamos una diferencia significativa en la expresión de miR-221 entre el grupo control y los demás grupos. Sin embargo, los microARN: miR-126 y miR-133b no mostraron diferencias significativas en la expresión entre grupos.

Compatibility Polymorphism Based on Long-Term Host-Parasite Relationships: Cross Talking Between Biomphalaria glabrata and the Trematode Schistosoma mansoni From Endemic Areas in Brazil.

Sympatric snail populations have been kept in the laboratory since the isolation of the parasite from the field. To evaluate the influence of the intermediate host in the infectivity of S. mansoni, this allopatric strain was compared to two sympatric strains, from different geographical origins, and with different time of maintenance in the laboratory. Snail-trematode compatibility was accessed for a total of nine possible combinations (three snail populations, three schistosome strains), using different charges of parasite: 1, 5, 10, and 15 miracidia/snail. Each S. mansoni strain was characterized according to its infectivity phenotype that reflects the efficiency of their infection mechanism and all B. glabrata populations were characterized according to its (in)compatible phenotype that reflects the level of (un)susceptibility they display. For all host-parasite combinations tested the dose-response relation indicated a trend for an increase in the infectivity of S. mansoni when higher miracidial doses were used. SmRES-2 presented the highest overall infectivity rate, especially in the SmRES-2/BgRES interaction with 15 miracidia/snail. However, SmRES was more infective to BgBAR than SmRES-2, indicating that SmRES strain was more infective at the first contact with this new host than after 2 years of interaction (SmRES-2). BgBAR presented the highest susceptibility to infection. SmRES and SmRES-2 are the same parasite strains. It seems that during these 2 years of interaction, BgBAR acted like a filter and shifted the compatibility polymorphism of the strain SmRES. SmRES-2 became more infective to BgRES (sympatric) than to BgBAR (allopatric), and conversely, SmRES was more infective to BgBAR (allopatric) than to BgRES (sympatric). This interplay suggests that epigenetic mechanisms are prompting these changes. This study concerns with infection of B. glabrata snails from different Brazilian localities with S. mansoni in allopatric and sympatric associations that will partially help in understanding the natural epidemiology of schistosomiasis within natural snail populations in watercourses. This work demonstrates that there is a shift on the compatibility polymorphism profile resulting from sympatric and allopatric interactions of B. glabrata and S. mansoni that constantly change during the time of interaction.

Unveiling the oxidative metabolism of Rhipicephalus microplus (Acari: Ixodidae) experimentally exposed to entomopathogenic fungi.

Rhipicephalus microplus is an important tick in tropical regions due to the high economic losses caused by its parasitism. Metarhizium anisopliae and Beauveria bassiana are well-known entomopathogenic fungi that can afflict R. microplus ticks. The development of new targets and strategies to control this parasite can be driven by studies of this tick's physiology. Recently, it was reported that when exposed to adverse physiological conditions, ticks can activate fermentative pathways, indicating transition from aerobic to anaerobic metabolism. Nevertheless, the precise mechanism by which entomopathogenic fungi influence R. microplus metabolism has not been clarified, limiting understanding of the tick-fungus association. Thus, the present study aimed to evaluate the effect of infection of ticks by M. anisopliae and B. bassiana on the amount of selected carboxylic acids present in the hemolymph, enabling increased understanding of changes previously reported. The results showed preservation in the concentrations of oxalic, lactic, and pyruvic acids in the hemolymph 24 and 48 h after dropping from cattle; while there were variations in the concentration of these carboxylic acids after infection of female ticks to M. anisopliae and B. bassiana. Significant increases were observed in the concentration of oxalic and lactic acids and significant reduction of pyruvic acid for both observation times (24 and 48 h) after infection by entomopathogenic fungi. These results indicate that B. bassiana and M. anisopliae infection alters the basal metabolism of R. microplus females, resulting in the activation of fermentative pathways.